1. Field of the Invention
The present invention relates to high flow steam carpet cleaning machines.
2. Discussion of the Prior Art
The machine of the present invention relates to high flow portable hot water extractors, also called portable steam carpet cleaners. These machines have almost always been self-contained. By self-contained it is meant it has a holding tank for its cleaning water and a large recovery tank for the dirty water. These machines work by pulling water from the holding tank with a high pressure pump, spraying it on the carpet and recovering it with a vacuum source forming a water pick-up area.
Traditionally, the main problem with steam carpet cleaning machines has been their over wetting of carpets. This over wetting is due to the inability of these machines to generate enough vacuum at the carpet. This inability has led to restricting the amount of water used in the cleaning process. This restriction in water flow has limited the cleaning ability of these machines.
The water recovery systems within these machines produces much less vacuum or suction at the carpet than the machine described herein, even though they often use the same type of vacuum motor. This is caused by three reasons: the much longer distance between their vacuum motor and water pick-up; the comparatively large volume of air contained in their recovery tanks; the comparatively large area the vacuum acts upon on the inside of their recovery tanks (i.e. the volume of the recovery tank).
All steam carpet cleaning machines have recovery tanks. These are the tanks which hold the recovered water sprayed onto the carpet. Other than the machine of the present application, there are only two other known types of portable steam carpet cleaning machines. Both of these types have similar recovery tanks:
1) Self-Contained Pull Behind Machines which have recovery tanks in the 7 to 10 gallon range; PA1 2) Box and Wand Machines which have recovery tanks in the 10 to 18 gallon range. PA1 1) It uses a much higher clear water flow (3 to 4 times higher than other machines) which rinses fibers more thoroughly than previously possible; PA1 2) Using the same or similar vacuum motor it generates such a high vacuum at the carpet that even with more than 3 times the water flow, it leaves carpets much dryer than other machines. It solves the over wetting problem associated with portable steam carpet cleaning machines; PA1 3) Operators can clean faster and more thoroughly than previously possible. This reduces labor cost and increases quality; PA1 4) The operating weight is less than half of most other machines. It is so small it can fit into the trunk of most cars. Most other machines need a truck for transportation; PA1 5) Because it is lightweight and of the straight upright position of the operators back when cleaning with the present machine, the chronic back problems commonly associated with carpet cleaners is greatly reduced; and PA1 6) It will increase indoor air quality in carpet environment after use due to its ability to clean carpet using higher flow rate of water.
The main difference with these two types of machines is that the box and wand type of machine has a vacuum hose running from the recovery tank to the cleaning wand. The self-contained pull behind type of machine has the cleaning wand connected directly to the recovery tank. None of these machine, however utilize a high flow of water however due to the inability to recover the water by the vacuum
How these recovery tanks work is as follows. A vacuum motor or motors which generates both air flow and water lift is mounted on the outside of the recovery tank. A vacuum hole in the recovery tank allows the vacuum generated by the vacuum motor to enter the tank. When the wand or water pick-up channel part of the machine makes contact with the carpet, it partially closes the system. The vacuum motor immediately starts removing air from the recovery tank. As air is removed from the recovery tank a vacuum or suction is exerted on both the inside area of the vacuum tank and the carpet that is under the water pick-up channel. This vacuum increases as more and more air is removed from the recovery tank.
Since all vacuum motors are limited in the amount of air they can remove per minute, it stands to reason that the smaller the volume of air in the recovery tank the faster the vacuum will act at the carpet under the water pick-up channel. Also since all vacuum motors are limited in the power they can generate, it stands to reason that the fewer square inches this power has to act upon the more response the vacuum system will have. Therefore, the lower volume of air and surface area within the recovery tank the faster the vacuum response.
In a large recovery tank much of the power generated by the vacuum motor is wasted by acting on the large inside volume of the recovery tank. To get as much vacuum to the carpet as possible, it is vitally important to reduce the volume of the recovery tank. By doing this you usually reduce the distance between the vacuum motor and the water pick-up.
Further, this does not resolve the main problem faced with prior art machines, namely low water flow rates to the carpet. Typical water flow rates for steam machines are less than one gallon per minute. This low flow rate reduces the ability of the machine to remove significant amounts of soil from the carpet. Thus, it is desirable to have a machine which introduces a high flow of water to the carpet while providing the ability to remove to sprayed water and to prevent the overwetting problems noted above.